On the basis of the observation of symptoms of bronchial obstruction in patients suffering from heart failure, the present inventors first showed that the administration of the cholinergic agonist methacholine to patients suffering from left ventricular failure caused a bronchial obstruction at doses identical to those which were active in asthmatic subjects, this effect not being observed in patients exhibiting coronary insufficiency but normal left ventricular function. In view of the fact that the vessels which irrigate the bronchi drain into the left heart, the present inventors administered methoxamine-HCl, a potent vasoconstrictor, as a pretreatment via the respiratory tract (inhalation), and they demonstrated that this administration of methoxamine enables the bronchoconstriction induced by the inhalation of methacholine to be prevented in these patients suffering from left ventricular failure. The inventors then demonstrated that the administration of methoxamine by inhalation was capable:
of decreasing the resistance of the airways in subjects suffering from decompensated left ventricular (pulmonary edema and subedema); and PA1 of increasing the exertion tolerance of patients suffering from compensated left ventricular failure, whether the latter is of ischemic origin or otherwise.